regex: Fix pcre2_jit_compile return value check
regex: Fix pcre2_jit_compile return value check

This returns 0 for success, and negative for failure.

saitoha/vte-sixel,saitoha/vte-sixel,thestinger/vte-ng,saitoha/vte-sixel,thestinger/vte-ng,thestinger/vte-ng